This Application relates to a piston actuated parking brake with is associated with service brakes, and wherein the parking brake is self adjusting.
Braking systems used for extremely large vehicles, such as large earth-moving vehicles, have typically included separate parking and service brake pistons. The service brake pistons are actuated by the operator to stop the vehicle. The parking brake locks the vehicle when parked. While these systems have been able to brake vehicles successfully, there are some deficiencies.
One deficiency relates to adjustment of the brakes due to wear on the friction material. The friction material contacts the vehicle rotor to retard rotation of the rotor, and thus stop the vehicle. With use, the friction material wears. As the friction material wears, the friction material becomes spaced further from the vehicle. The pistons move this friction material into contact. When wear occurs, it is necessary to move the pistons and friction material closer to the rotor such that the system compensates for the wear.
In the prior art systems, which used unconnected service and parking brake pistons, it was difficult to get corresponding adjustment between the service and parking pistons.